The BGS Lexicon of Named Rock Units — Result Details

Gouther Crag Breccia Member

Computer Code: GRCG Preferred Map Code: GrCg
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: A massive, poorly sorted volcaniclastic breccia, comprising heterolithic volcanic clasts, including abundant pink-weathered rhyolite clasts.
Definition of Lower Boundary: The abrupt change from bedded volcaniclastic sandstone within the Mardale Sandstone Formation to volcaniclastic breccia.
Definition of Upper Boundary: Taken at the sharp base of the overlying thin unit of bedded volcaniclastic sandstone, which is succeeded by massive, weakly eutaxitic, dacitic lapilli-tuff.
Thickness: To 180m
Geographical Limits: Swindale, Cumbria, between Dry Grove Gill [NY 510 122] and Mullender [NY 522 132].
Parent Unit: Mardale Sandstone Formation (MRL)
Previous Name(s): Gouther Crag Member (-940)
Alternative Name(s): none recorded or not applicable
Type Area  Gouther Crag, 500m south of Truss Gap, Swindale, Cumbria. 
Millward, D, 2002. Geology of the area between Haweswater and Shap. British Geological Survey Research Report RR/02/02 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E030 E039